I am not able to view craigslist ads on my imac nor pc using firefox. I get the following error message at the top of a search https://discussions.apple.com/thread/2491900?start=0&tstart=0. when I click on the ad I receive error - Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. I do not have this issue if I use Safari or IE however I prefer to FF. Thanks in advance for any assistance.